The present invention relates to analytical assay procedures for determining the amount of an analyte present in a liquid test sample. In particular, the present invention relates to the determination of an analyte in a liquid test sample involving analytical reactions between the analyte and one or more analytical reagents requiring sequential, manipulative steps to make such determination.
Various analytical procedures have been developed for the determination of analytes of industrial, environmental and particularly medical significance. In many instances, such analytical procedures involve a number of analytical reactions and manipulative steps which must be performed sequentially in order to carry out an assay protocol. Such sequential steps, including such manipulations as pipetting, centrifugation, periods of incubation, separation steps, and the like, are subject to errors that can lead to inaccurate results. Although various devices have been developed in an attempt to automate or otherwise simplify such manipulative steps, such devices are often cumbersome and require trained, experienced technicians for their operation. In some instances, such devices still require a number of manual manipulative steps during the course of carrying out an assay protocol.
For example, U.S. Pat. No. 4,673,653 describes a method for performing biological analysis of a liquid sample employing a compartmentalized plastic container which requires a number of centrifugation steps. The container comprises a storage chamber for the liquid sample, a calibration cell, a plurality of storage chambers for various reaction liquids, and a reaction vat. The various chambers, calibration cell and reaction vat are interconnected by capillary ducts for communicating liquids therebetween by centrifugal force. In carrying out the biological analysis, successive centrifugation steps are performed with the angular position of the container being selected for each centrifugation step as a function of the orientation of a particular capillary duct relative to the direction of the centrifugal force in order to facilitate manipulation of a liquid disposed in the device.
U.S. Pat. No. 4,690,801 describes a manually manipulated device comprising a disk having a thin flexible membrane applied to one side thereof which defines a conduit and a plurality of reagent reservoirs isolated from one another by frangible seals. An assay tube is situated at one end of the conduit and a sample injection reservoir is situated at the other end of the conduit. The disk fits into a base member, and a cover member having a roller bar fits over the base wherein the roller bar engages the surface of the disk. In operating the device, the cover is rotated relative to the disk wherein the roller bar applies pressure to the reservoirs to rupture the frangible seals and force the reagents from their respective reservoirs into the conduit for the purpose of carrying out the assay.
Accordingly, it is an object of the present invention to provide a device for performing sequential analytical assay procedures which does not involve centrifugation or other mechanically generated forces.
Another object of the present invention is to provide a device for performing sequential analytical assay procedures which requires a minimal number of manual manipulation steps.
Further, it is an object of the present invention to provide a device for performing sequential analytical assay procedures which does not involve complicated manufacturing or assembly processes.
Still another object of the present invention is to provide a device for performing sequential analytical assay procedures which is easy to manipulate and operate.
Still further, another object of the present invention is to provide a device for performing sequential analytical assay procedures which is easily adaptable to a physician's office or a small, clinical laboratory.